Power-driven hydroplane watercraft



July 1, 1969 w. D. WILSON 3,452,698

POWER-DRIVEN HYDROPLANE WATERCRAFT F Filed Feb, 1, 1968 Sheet Of 4 FIG.

July 1, 1969 w. D. WILSON 3,452,698

POWER-DRIVEN HYDROPLANE WATERCRAFT Filed Feb. 1, 1968 Sheet 3 of 4 July 1, 1969 w. D. WILSON v POWER-DRIVEN HYDROPLANE WATERCRAFT Sheet Filed Feb. 1, 1968 July 1, 1969 w. D. WILSON POWER'DRIVEN IIYDROPLANE WATERCRAFT Filed Feb. 1, 1968 Sheet United States Patent US. Cl. 11466.5 7 Claims ABSTRACT OF THE DISCLOSURE A lenticular hydroplane watercraft having its plane of maximum diameter relatively horizontal and its height small relative thereto, the parts above and below said plane comprising similar hollow spheroidal segments which are joined together at their chordal extremities, the lower segment sitting on a relatively narrower fiat hydroplane panel which at the common centerline is tangential to the curvature of the segment and parallel to said plane, and there being a centrally positioned open cockpit with a vertical stern well passing through the hull, to house a conventional outboard power unit having its screw facing astern below the hydroplane panel.

This invention relates to power-driven hydroplane watercraft, and has for its object the provision of an improved form of such watercraft.

According to the invention a hydroplane watercraft is provided with a hull of lenticular shape whereof the maximum diameter lies on a relatively horizontal plane and wherein the overall height is small in relation to the said maximum diameter of the parts above and below the plane of the maximum diameter formed from similar hollow spheroidal segments which are joined together in a watertight manner at their respective chordal extremities, there being in the part above the plane of maximum diameter a cockpit opening so positioned and arranged relative to a predetermined fore-and-aft amidships line that the space within the hull for accommodation of crew and cargo is adjacent to and disposed substantially symmetrically about the centre of the said fore-andaft amidships line, and there being attached to the hull part below the plane of maximum diameter a substantially fiat hydroplane panel which is parallel to the said plane and at a distance therefrom such that its underside surface is substantially tangential to the curvature of the said hull part on the fore-and-aft amidships line the said hydroplane panel having a width less than the diameter of the hull and being positioned so that its sides are parallel to and equidistant from the fore-and-aft amidships line and its forward end is located at or about the athwartship centreline of the hull by suitable extensions thereof the stern end of the said hydroplane panel being terminated at a position astern of the hull by a pair of identical semicircular blade-extensions of the panel the diameter of each said extension being less than half the width of the said panel, and there being immediately aft of the cockpit a rectangular well passing vetrically through the hull and hydroplane panel the said well being on the fore-and-aft amidships line with two of its sides parallel thereto and equidistant therefrom and that part of the well which is within the hull being provided with bulkheads to prevent ingress of water to the interior of the hull one of the transverse bulkheads being suitably stiifened and shaped to form a mounting element for a conventional type of outboard power unit which in this instance is mounted within the well so that its driving screw is facing the stern and below the level of the hydroplane panel.

Preferably the overall height of the hull excluding superstructure is in the range between 0.22 and 0.50 of 3,452,698 Patented July 1, 1969 "ice the maximum diameter thereof, and the preferred width of the hydroplane panel is in the range between one half and three quarters of the hull diameter.

The hollow spheroidal segments which form the hull are preferably identical and are substantially circular when viewed from above with the chordal plane horizontal, the spheroidal surface shape of the said segments preferably being such that the highest point relative to the chordal plane is on the predetermined fore-and-aft amidships line but to one side of the centre thereof, the two segments forming the hull being so orientated rela tive to one another that the highest point of curvature of the segment above the plane of maximum diameter is on the fore-and-aft amidships line and forward of the athwartship centre-line, and the corresponding point of the segment below the said plane is on the fore-and-aft amidships line but abaft the athwartship centre-line.

The means whereby the hollow spheroidal segments are joined together at their chordal extremities may include resilient sealing means which is extended beyond the peripheral extremities of the segments to form a resilient protective fender around the hull.

Around the cockpit opening there may be gunwale extensions of the hull surface to prevent the entry of spray or splashing water into the hull, and a suitable handrail may be provided for the convenience of the crew.

The transverse bulkhead which forms the mounting element for the power unit may include rapidly operable lifting means for raising the power unit so that its driving screw is withdrawn into the well of the hull when beaching the era-ft.

The hull may be fabricated from sheet metal or preformed laminated timber but preferably is made from a reinforced synthetic resin material known as fibreglass.

An embodiment of the invention will now be described by way of example, with reference to the accompanying drawings wherein,

FIGURE 1 is a diagrammatic elevation showing the basic contour of the cross-sectional shape of the hull on the fore-and-aft amidships line with the forward part of the hull to the left of the view,

FIGURE 2 is a plan view of the hull as seen from above,

FIGURE 3 is a plan view of the hull as seen from below,

FIGURE 4 is a general view of the hull looking in a downward direction towards the after starboard quarter,

FIGURE 5 is a view looking into the cockpit in a direction substantially at right-angles to the fore-and-aft amidships line,

FIGURE 6 is a scrap view showing how the power unit fixes to the forward transverse bulkhead of the well, and

FIGURE 7 is a scrap view showing the resilient sealing means between the upper and lower spheroidal segments.

As shown in FIGS. 1 and 2, the hull 1 is of lenticular shape having its maximum diameter d on a horizontal plane, the overall height of the hull being in the range between 0.22 and 0.50 of the said maximum diameter d, which hull comprises similar upper and lower hollow spheroidal segments 2 and 3 respectively, of substantially the same basic contour joined together at their respective chordal extremities, the highest point pof the basic contour of the upper segment 2 being on the fore-and-aft amidships line but forward of the athwartship centre-line by an amount in the range of 0.1 to 0.25 of the hull diameter d, and the corresponding point p of the lower segment 3 being on the fore-and-aft amidships line but abaft of the athwartship centre-line.

-At the joint between the chordal extremities of the two spheroidal segments there is a resilient sealing means 16 3 which extends beyond the peripheral extremities of the 1slegments to form a resilient protective fender round the ull.

Below and substantially parallel to the plane of maximum diameter of the hull and arranged so that its underside surface is substantially tangential to the curvature of the lower segment 3 of the hull on the fore-and-aft amidships line, is a substantially flat hydroplane panel 4 of a width in the range 0.5 to 0.75 of the hull diameter d, which panel has its sides parallel to and equidistant from the fore-and-aft amidships line, and its forward end located at or about the athwartship centre-line of the hull, and its rear end terminating, at a position in the range between 0.1 and 0.17 of the hull diameter d astern of the hull, in a pair of semicircular extensions each of less than half the width of the panel, the sides and rear of the said panel being supported from the lower segment 3 of the hull by extensions 5 and support struts 6.

Opening into the hull from the upper segment 2 is a cockpit 7 so positioned relative to the fore-and-aft amidships line that the space for accommodation of crew and cargo is adjacent to and disposed substantially symmetrically about the centre of the said fore-and-aft amidships line, and there being around the front and sides of the cockpit opening, gunwhale extensions 8 of the hull to prevent the ingress of splashing water or spray into the hull. A handrail 9 is provided for the convenience of the crew. Mounted on the floor of the cockpit there may be footclamps 10 of the kind used, for example, on waterskis.

Immediately aft of the cockpit and on the fore-and-aft amidships line of the hull and with two of its sides parallel thereto and equidistant therefrom, there is a rectangular well 11 passing vertically through the hull and the hydroplane panel, the part of the well within the hull being provided with bulkheads to prevents the ingress of water to the hull, and the forward transverse bulkhead 12 being suitably stiffened and shaped to form a mounting element for a conventional type of outboard power unit 13 arranged so that its driving screw 14 is facing the stern and below the level of the hydroplane panel. The said forward transverse bulkhead 12 may be provided with an auxiliary power unit clamping plate (not shown) which includes rapidly operable lifting means for raising the power unit to withdraw its driving screw into the said well. The upper part of the well 11 is opened out to form a recess 15 to house the body of the power unit.

In use, forward motion resulting from the thrust produced by the driving screw of the power unit causes the hydroplane panel to raise the hull relative to the surface of the water in known manner and so that the most deeply immersed point of the underwater part of the lower spheroidal segment of the hull remains on the fore-and-aft amidships line but has moved to a position astern of the athwartship centre-line, in which condition the craft performs in a similar manner to a conventional hydroplane watercraft when engaged in normal point-to-point cruising. When, however, maximum maneuverability is required, it is provided by causing the craft to heel towards a direction to be taken, as for example, by relative lateral displacement of the weight of the crew, so that the said most deeply immersed point of the underwater part of the lower spheroidal segment is displaced transversely relative to the fore-an-aft amidships line of the hull and the line of thrust of the screw of the power unit, such displacement causing the immersed part of the spheroidal segment to provide an asymmetric braking effect tending to cause the craft to pivot about the said point, in a tight turn.

It has been found that with the controller of a craft according to this invention standing in the cockpit in the attitude generally adopted for water-skiing, the craft will, at high speed, follow a pre-determined zig-zag course around a series of obstacles in response to swaying motions of the body of the said controller.

What is claimed is:

1. A hydroplane watercraft having a hull of lenticular shape whereof the maximum diameter lies on a relatively horizontal plane and wherein the overall height is small in relation to the said maximum diameter the parts above and below the plane of the maximum diameter being formed from similar hollow spheroidal segments which are joined together in a watertight manner at-their respective chordal extremities, there being in the part above the plane of maximum diameter a cockpit opening so positioned and arranged relative to a predetermined foreand-aft amidships line that the space within the hull for accommodation of crew and cargo is adjacent to and disposed substantially symmetrically about the centre of the said fore-and-aft amidships line, and there being attached to the hull part below the plane of maximum diameter a substantially flat hydroplane panel which is parallel to the said plane and at a distance therefrom such that its underside surface is substantially tangential to the curvature of the said hull part on the foreand aft amidships line the said hydroplane panel having a width less than the diameter of the hull and being positioned so that its sides are parallel to and equidistant from the fore-and-aft amidships line and its forward end is located at or about the athwartship centreline of the hull by suitable extensions thereof the stem end of the said hydroplane panel being terminated at a position astern of the hull by a pair of identical semicircular blade-extensions of the panel the diameter of each said extension being less than half the width of the said panel, and there being immediately aft of the cockpit a rectangular Well passing vertically through the hull and hydroplane panel the said well being on the fore-and-aft amidships line with two of its sides parallel thereto and equidistant therefrom and that part of the well which is within the hull being provided with bulkheads to prevent ingress of water to the interior of the hull one of the transverse bulkheads being suitably stiffened and shaped to form a mounting element for a conventional type of outboard power unit which in this instance is mounted within the well so that its driving screw is facing the stern and below the level of the hydroplane panel.

2. A hydroplane watercraft in accordance with claim 1 wherein the overall height of the hull excluding superstructure is in the range between 0.22 and 0.50 of the maximum diameter thereof, and the width of the hydroplane panel is in the range between one half and threequarters of the hull diameter.

3. A hydroplane watercraft in accordance with claim 1 wherein the hollow spheroidal segments which form the hull are substantially identical and are susbtantially circular when viewed from above with the chordal plane horizontal, the spheroidal surface shape of the said segments being such that the highest point relative to the chordal plane is on the predetermined fore-and-aft amidships line but to one side of the centre thereof, the two segments forming the hull being so orientated relative to one another that the highest point of curvature of the segment above the plane of maximum diameter is on the fore-and-aft amidships line and forward of the athwartship centre-line, and the corresponding point of the segment below the said plane is on the fore-and-aft amidships line but abaft the athwartship centre-line.

4. A hydroplane watercraft in accordance with claim 1 wherein the means whereby the hollow spheroidal segments are joined together at their chordal extremities in cludes resilient sealing means which is extended beyond the peripheral extremities of the segments to form a resilient protective fender round the hull.

5. A hydroplane watercraft in accordance with claim 1 wherein around the cockpit opening there are gunwale extensions of the hull surface to prevent the entry of spray or splashing water into the hull, and wherein a suitable handrail is provided for the convenience of the crew.

6. A hydroplane watercraft in accordance with claim 1 wherein the transverse bulkhead which forms the mounting element for the power unit includes rapidly operable lifting means for raising the power unit so that its driving screw is withdrawn into the well of the hull when beaching the craft.

7. A hydroplane watercraft in accordance with claim 1 wherein the hull is fabricated from a reinforced synthetic resin material such as that known as fibreglass, or from sheet metal, or from preformed laminated timber.

References Cited UNITED STATES PATENTS ANDREW H. FARRELL, Primary Examiner.

US. Cl. X.R. 

